LYWSD03MMC-push-to-ha.sh

#!/bin/bash
#
# LYWSD03MMC read out temperature & humidity
# report it to Home Assistant as a new sensor over MQTT
#
# 1. Setup the MAC address (hcitool lescan if you don't know) and MQTTT parameters
# 2. Initialize the MQTT structure: ./push-to-ha.sh init
# 3. Send in the reading: ./push-to-ha.sh
#
# Setup a periodic cron job -> profit!

# Sensor MAC address
MAC="A4:C1:38:12:34:56"

# MQTT parameters
MQTT_SERVER="192.168.10.2"
MQTT_PORT=1883
MQTT_USERNAME=""
MQTT_PASSWORD=""
MQTT_CLIENTID="officesensor_bd8041d0cdf131a6ba4e5b3360b8bc5a"
MQTT_TOPIC="homeassistant"
MQTT_DEVICENAME="officesensor"

registerTopic () {
    mosquitto_pub \
        -h $MQTT_SERVER \
        -p $MQTT_PORT \
        -u "$MQTT_USERNAME" \
        -P "$MQTT_PASSWORD" \
        -i $MQTT_CLIENTID \
        -t "$MQTT_TOPIC/sensor/"$MQTT_DEVICENAME"_$1/config" \
        -m "{
            \"name\": \""$MQTT_DEVICENAME"_$1\",
            \"unit_of_measurement\": \"$2\",
            \"state_topic\": \"$MQTT_TOPIC/sensor/"$MQTT_DEVICENAME"_$1\",
            \"icon\": \"mdi:$3\"
        }"
}

pushMQTTData () {
    mosquitto_pub \
        -h $MQTT_SERVER \
        -p $MQTT_PORT \
        -u "$MQTT_USERNAME" \
        -P "$MQTT_PASSWORD" \
        -i $MQTT_CLIENTID \
        -t "$MQTT_TOPIC/sensor/"$MQTT_DEVICENAME"_$1" \
        -m "$2"
}


# Initialize HA MQTT sensor
if [ "$1" = "init" ]; then
	registerTopic "temperature" "°C" "temperatur"
	registerTopic "humidity" "%" "humidity"
	echo "Done."
	exit 0;
fi;

# Query the temp & humidity sensor over BLE
bt=$(timeout 15 gatttool -b $MAC --char-write-req --handle='0x0038' --value="0100" --listen 2>&1 |tail -n1)

if [ "$?" -ne 0 -o -z "$bt" ]; then
	echo "Reading failed";
	exit 1;
fi;


reading_hex=$(echo $bt |cut -d ':' -f 2)
temp_hex=$(echo $reading_hex |awk -F ' ' '{print $2$1}' | tr [:lower:] [:upper:])
humi_hex=$(echo $reading_hex |awk -F ' ' '{print $3}' | tr [:lower:] [:upper:])
temp100=$(echo "ibase=16; $temp_hex" |bc)
temp=$(echo "scale=2;$temp100/100" |bc)
humi=$(echo "ibase=16; $humi_hex" |bc)

echo "Temp: $temp C"
echo "Humidity: $humi %"
pushMQTTData "temperature" "$temp"
pushMQTTData "humidity" "$humi"